Dehydrator drum construction



2 Sheets-Sheet 1 Filed Sept. 30, 1953 INVENTOR.

June 26, 1956 c, FRENCH 2,752,130

DEHYDRATOR DRUM CONSTRUCTION 2 Sheets-Sheet 2 Filed Sept. 30, 1953 JNVENTOR.

ATTORNEYfl United States Patent DEHYDRATOR DRUM CONSTRUCTION Henry C. French, Elm Grove, Wis., assignor to Arnold Dryer Co., Milwaukee, Wis., a corporation of Wiscousin Application September 30, 1953, Serial No. 383,230

Claims. (Cl. 25989) This invention relates to improvements in dehydrator drum construction.

The invention relates more particularly to the manufacture of dehydrators for forage crops or the like, of the general type shown in Arnold Patent No. 1,988,677. In this type of dehydrator there are concentric drums which rotate as a unit, and material to be dried is caused to travel first through the inner drum, then in a reverse direction through a circular chamber formed between the outer surface of the inner drum and the inner surface of an intermediate drum, and then in the direction which it originally travelled between the outer surface of the intermediate drum and the inner surface of an outer drum. In this type of dryer it is necessary to utilize material showering flights which project both inwardly and outwardly from the inner and intermediate drums. Heretofore, the formation of these drums, as well as the connection of the flights thereto, has been expensive and time consuming, because the flights have to be either Welded, bolted or riveted in position. In addition with conventional methods, there is considerable longitudinal welding required in the manufacture of the drums proper.

It is a general object of the present invention to provide an improved dehydrator drum construction which materially simplifies manufacture and reduces the cost thereof.

A further object of the invention is to provide a dehydrator drum construction wherein the drum is formed of a plurality of longitudinal sections which, in the preferred embodiment, are connected together in a manner to eliminate the necessity of the usual welds.

A further object of the invention is to provide a construction as above described wherein the longitudinal sections have a cross-sectional shape which in itself forms material showering flights on both sides of the drum to thereby eliminate the necessity of securing separate flights in position during manufacture.

A more specific object of the invention is to provide a dehydrator drum construction as above described wherein the longitudinal sections which form the drum have a cross-sectional shape to form hollow longitudinally extending flights which project from one of the surfaces of the drum, the cross-sectional shape being preferably such as to also form other flights on the other side of the drum.

A further more specific object of the invention is to provide a dehydrator drum construction which comprises a plurality of longitudinal sections, each section having one edge formed with a longitudinally extending flange having a return bend, and each section having its other edge formed with an angular flange which is clamped between the first mentioned flange and return bend of an adjacent section to maintain the sections in assembled condition, it being preferred to also utilize additional means such as longitudinally spaced local crimps in the flanges and return bend to additionally hold the sections in drum forming position.

2,752,136 Patented June 26, 1956 A further object of the invention is to provide a dehydrator drum construction as above described wherein the hollow flights which project from one side of the drum are open on the other side so as to provide pockets and so as to also provide automatic cooling of the interiors of the flights as the drum rotates, this being particularly advantageous in connection with the inner drum of a triple drum dryer, where said flights are subjected to the action of hot gases of combustion.

With the above and other objects in view the invention consists of the improvements in dehydrator drum construction, and all of its parts and combinations, as set forth in the claims, and all equivalents thereof.

In the accompanying drawings, illustrating one complete embodiment of the preferred form of the invention, wherein the same reference numerals designate the same parts in all of the views:

Fig. 1 is a view of the intermediate drum of a triple drum dehydrator, partly in side elevation and partly in longitudinal section, the middle portion of the drums being broken away;

Fig. 2 is a fragmentary sectional view, on an enlarged scale, taken along the line 22 of Fig. 1;

Fig. 3 is a transverse sectional view through all three drums of a triple drum dehydrator looking in the opposite direction from Fig. 2; and

Fig. 4 is a fragmentary sectional view showing the preferred method of securing the drum forming sections together by clamping and spot-crimping.

Referring more particularly to the drawing, the nu merals 10 and 11 designate end heads of the intermediate drum 9 of a dehydrator, which heads are connected by longitudinally extending drum forming sections 12. These sections are arranged as shown in Figs. 1 and 2 to form a cylinder. Each one of the sections 12 has a crosssectional shape which provides a hollow longitudinally extending flight 13 having sidewalls 14 and 15. At the outer edge of the wall 15, the metal is bent to extend at an obtuse angle with respect to the wall 15 as at 16, to provide a relatively flat peripheral portion. The longitudinal edge of the portion 16 is bent outwardly to form the longitudinal flange 17. The wall 14 of the hollow flight 13 projects outwardly beyond the flat portion 16 to provide an outside flight projection 18 and it is then formed with a return bend 19, the flange 17 of an adjacent section being clamped between the projection 18 and its return bend 19.

It is usually necessary to have additional means to hold the flanges 17 in the position of Fig. 4. While various means may be used, it is a feature of the preferred form of the invention to employ spot-crimps 20 which indent the material of the return bend 1Q, flange 17, and flight 18 in dot-like areas which are longitudinally spaced throughout the length of the drum. This is an inexpensive and simple method of securing longitudinal sections together, and the preferred form of the invention contemplates the use of the method of Fig. 4. it may, however, be desirable, in certain installations, to substitute spot-welding, bolts or rivets for the spot-crimping. These latter methods, however, increase the cost. It is to be understood that one aspect of this invention contemplates the assembly of drum sections in the manner shown in Figs. 2 and 4, regardless of the specific cross-sectional shape of the sections.

Suitably secured to the head it), and projecting in- .wardly therefrom are circumferentially spaced gussets 21 'which may support a circular band 22. The latter is adapted to receive one end of an inner drum 23 (see Fig. 3). The other end of the inner drum may project through a circular opening 24 in the head 11 of the intermediate drum.

The outer drum 25, shown in Fig. 3, may be conventional and may have separate lineal flights 26 secured to its inner periphery to project inwardly therefrom as illustrated. These flightsmay be secured in any well known manner. The intermediate drum is suitably supported in concentric position within the outer drum by means including the bolts 27, which secure circular bands 28 and 29 together, and by spaced gussets 39 which maintain the intermediate drum in concentric position. This method of assembling the three drums as a unit forms no part of the present invention, but is referred to merely for purposes of background.

The inner drum is smaller than the intermediate drum, but is otherwise formed in the same manner from longitudinal sections, which, while smaller, are otherwise identical in construction to the longitudinal sections 12 of Figs. 1, 2 and 4. For this reason the inner drum will not be described in detail, it being understood that the parts or the inner drum are designated by the same numerals used in describing Figs. l and 52, except that prime marks are added.

In the improved construction it will be noted that in addition to the hollow flights 13 which project inwardly I from the inner and intermediate drums that there are, in efiect, additional hollow flights which projectin the opposite direction and which are definedby the walls 14, 16 and 15. These outwardly directed hollow flights are designated generally by the numeral 31 for the intermediate drum and 31' for the inner drum. In addition there are longitudinally extending flight projections which are formed by the structure of Fig. 4 and which project outwardly beyond the hollow flights 31. The three thicknesses which form these flight projections are designated in their entirety by the numerals 32 for the intermediate drum and 32 for the inner drum. 7

During use of the dehydrator, gases of combustion are directed into one end of the inner drum 23. These gases, together with the heated air currents subject the flights 13, which project inwardly from the inner drum, to considerable heat. However, the air which is between the inner drum and the intermediate drum is substantially cooler and this cooler air may enter the hollow interiors of the flights 13' to prevent overheating. Material such as chopped alfalfa, which is fed into the inner drum is picked up by the sides 14 or the inwardly directed hollow flights and is moved upwardly while the drums rotate in the direction shown by the arrow in Fig. 3. Near the top, the material will fall by gravity and be showered downwardly through the heated air currents. Material which is passing between the inner drum and the intermediate drum is acted upon in the same way by the flights 13 which project from the inside of the intermediate drum. in addition, material is carried on the outer side of the inner drum by the wall portions 15' and by the projecting flight portions 32. Material which is passing between the outer surface of the intermediate drum and the outer drum is, of course, acted upon by the conventional flights 26 which project inwardly from the outer drum, and is also acted upon by'the wall portions 15 and flights 32 on the outer surface of the intermediate drum.

It is thus apparent that in addition to providing a simple and inexpensive drum construction for the inner and intermediate drums, the present invention also improves the flight construction to produce more effective showering of the material through the heated air currents, there being hollow flights 13 and 13 projecting inwardly, and hollow flights 31 and 31 projecting outwardly, as well as additional outwardly projecting flights 32 and 32 In addition to the above, the construction provides a simple type of cooling for those flights 31' which project inwardly from the inner drum, which cooling is due to the cooler air entering the hollow interiors of said flights.

In the claims the phrase outer surface of the cylinder" or periphery of the cylinder contemplates the surface 4, 16 of Fig. 2 or the surface 16' of the inner cylinder, as shown in Fig. 3.

Various changes and modifications may be made without departing from the spirit of the invention, and all of such changes are contemplated as may come within the scope of the claims.

What I claim is:

1. A dehydrator drum construction comprising a plurality of longitudinal sections arranged to form a cylinder, each section having a cross-sectional shape which forms a hollow longitudinally extending flight projecting inwardly from the inner surface of the cylinder, the hollow portion of the flight being open on the outer side of the cylinder to provide for cooling of the flight, there being a longitudinally extending relatively flat part in each section which extends at an angle from said hollow flight adjacent said open side, and said flat part having an edge forming one of the edges of the section which has a flange bent outwardly to project beyond the outer surface of i the cylinder, the opposite edge of the section having a longitudinally extending projecting part which fits against the bent flange of an adjacent section, and means located outwardly beyond the outer surface of the cylinder for securing said part and bent flange together to hold the sections in assembled position. p

2. A dehydrator drum construction comprising a plurality of longitudinal sections arranged to form a cylinder, each section having a cross-sectional shape which forms a hollow longitudinally extending flight projecting inwardly from the inner surface of the cylinder, the hollow portion of the flight being open on the outer side of the cylinder to provide for cooling of the flight, there being a longitudinally extending relatively flat part in each section which extends at an angle from said hollow flight adjacent said open side, and said flat part having an edge forming one of the edges of the section which has a flange bent outwardly to project beyond the outer surface,

of the cylinder, the opposite edge of the section having a lonigtudinally extending part which projects beyond the outer surface of the cylinder and which fits against the bent flange of an adjacent section, and means including longitudinally spaced spot crimps in said part and bent flange to hold the latter and the sections in assembled condition.

3. A dehydrator drum construction comprising a plurality of longitudinal sections arranged to form a cylinder, each section having a cross-sectional shape which forms a hollow longitudinally extending flight projecting in wardly from the inner surface of the cylinder, the hollow portion of the flight being open on the outer side of the cylinder to provide for cooling of the flight, each section having a longitudinally extending relatively flat part extending at an angle from said hollow flight adjacent said open side, and said flat part having an edge forming one or the edges of the section which has a flange bent outwardly to project beyond the outer surface. of the cylinder, the opposite edge of the section having a longitudinally extending part which projects beyond the outer surface of the cylinder and which fits against the bent flange of an adjacent section, and means including a return bend on said part clamping said bent flange in position .to hold the sections in assembled condition.

4. A dehydrator drum construction comprising a plurality of longitudinal sections arranged to'form'a cylinder, each section having a cross-sectional shape which forms a hollow longitudinally extendingiflight projecting inwardly from the inner surface of the cylinder, the hollow portion of the flight being open on the outer side of the cylinder tovprovide for cooling of the flight, each section having a longitudinally extending relatively :flat part extending at an angle from said hollow flight adjacent said open side, and said flat part having an edge forming one of the edges of the section which has a flange bentoutwardly to project beyond the outer surface of the cylinder, the opposite edge of the section having a longitudinally extending part which projects beyond the outer surface of the cylinder and which fits against the bent flange of an adjacent section, a return bend on said part for clamping said bent flange between said part and return bend, and longitudinally spaced spot crimps in said return bend, flange, and part for additionally holding the sections in assembled condition.

5. A dehydrator drum construction comprising a plurality of longitudinal sections arranged to form a cylinder having a periphery, each section having a crosssectional shape which forms a hollow longitudinally extending flight projecting inwardly from the inner surface of the cylinder and a longitudinally extending flight projecting outwardly of the outer surface of the cylinder from one edge of the section, the opposite edge of each section having an outwardly bent flange, and means located outwardly beyond the periphery of the cylinder for securing said outwardly bent flange of one section to the outwardly projecting flight of another section to hold the sections in assembled condition.

6. A dehydrator drum construction comprising a pinrality of longitudinal sections arranged to provide a cylinder, each section having a cross-sectional shape which forms a hollow longitudinally extending flight projecting inwardly from the inner surface of the cylinder and a longitudinally extending flight projecting outwardly from the outer surface of the cylinder, at one edge of the section, said last flight having a return bend accessible from the outside of the cylinder, the opposite edge of each section having an outwardly bent flange which is clamped between the outwardly projecting flight and return bend of an adjacent section to hold the sections in assembled condition.

7. A dehydrator drum construction comprising a plurality of longitudinal sections arranged to provide a cylinder, each section having a cross-sectional shape which forms a hollow longitudinally extending flight projecting inwardly from the inner surface of the cylinder and a longitudinally extending flight projecting outwardly from the outer surface of the cylinder, at one edge of the section, said last flight having a return bend accessible from the outside of the cylinder, the opposite edge of each section having an outwardly bent flange clamped between the outwardly projecting flight and return bend of an adjacent section to hold the sections in assembled condition, and spot crimps at longitudinally spaced intervals in said flight, return bend, and flange for further holding the parts in assembled condition.

8. A dehydrator drum construction comprising a plurality of longitudinal sections arranged to provide a cylinder, each section having a cross-sectional shape which forms a hollow longitudinally extending flight projecting inwardly from the inner surface of the cylinder and a longitudinally extending flight projecting outwardly from the outer surface of the cylinder, at one edge of the section, said last flight having a return bend accessible from the outside of the cylinder, the opposite edge of each section having an outwardly bent flange clamped between the outwardly projecting flight and return bend of an adjacent section to hold the sections in assembled condition, and externally accessible means at longitudinally spaced intervals in said flight, return bend, and flange for further holding the parts in assembled condition.

9. A dehydrator drum construction comprising a plurality of longitudinal sections arranged to form a cylinder, each section having a cross-sectional shape which forms a hollow longitudinally extending flight projecting inwardly from the inner surface of the cylinder, the hollow portion of the flight being open on the outer side of the cylinder to provide for cooling of the flight and each section having at one longitudinal edge a flange bent outwardly to project beyond the outer surface of the cylinder, the opposite edge of the section having a longitudinally extending part which fits against the bent flange of an adjacent section, and means located outwardly beyond the outer surface of the cylinder for securing said part and bent flange together to hold the sections in assembled position 10. A dehydrator drum construction comprising a plurality of longitudinal sections arranged to form a cylinder, each section having a cross-sectional shape which forms a hollow longitudinally extending flight projecting inwardly from the inner surface of the cylinder, the hollow portion of the flight being open on the outer side of the cylinder to provide for cooling of the flight, there being a longitudinally extending part in each section which extends laterally from said hollow flight adjacent said open side, and said part having an edge forming one of ,the edges of the section which has a flange bent outwardly to project beyond the outer surface of the cylinder, the opposite edge of the section having a longitudinally extending projecting part which fits against the bent flange of an adjacent section, and means located outwardly beyond the outer surface of the cylinder for securing said part and bent flange together to hold the sections in assembled position.

References Cited in the file of this patent UNITED STATES PATENTS 934,712 Cunarner Sept. 21, 1909 1,009,225 Cummer Nov. 21, 1911 1,240,029 Darley Sept. 11, 1917 1,417,617 McNeil May 30, 1922 2,063,446 Lanzi Dec. 8, 1936 

